1. Field of the Invention
The present invention relates to a liquid detergent composition which exhibits enhanced detergency and anti-redeposition properties as well as excellent freeze/ thaw and low temperature storage stability.
2. Description of the Related Art
Padron et al, U.S. Pat. No. 4,532,062 disclose aqueous liquid detergent compositions which exhibit good freeze/thaw and low temperature stability. The Padron composition contains hydroxypropyl methylcellulose (HPMC) in a liquid formulation together with builders and anionic and nonionic surfactants. Padron et al. do not include a graft copolymer of polyethylene glycol and a vinyl ester.
Bevin, U.S. Pat. No. 4,020,015 discloses a process whereby a cellulose containing ether linked anti-redeposition agent is combined with a copolymer of polyethylene glycol and polyethylene teraphthalate and the condensation product of polyethylene glycol and adipic acid and caprolactam or hexamethylene diamine or salts of caprolactam or hexamethylene diamine with adipic acid. The copolymer of Bevin is not the graft copolymer of the present invention and no mention is made in Bevin of a synergism between the graft copolymer of the present invention and a nonionic cellulosic anti-redeposition agent (e.g. HPMC).
Dean et al, U.S. Pat. No. 3,523,088 disclose an anti-redeposition agent and built detergent composition for use in washing synthetic fibers, fabrics, synthetic cotton blends, cotton fabrics and mixtures thereof. The anti-redeposition agent is a blend of carboxymethylcellulose and hydroxypropyl methylcellulose. There is no teaching of using a graft copolymer such as disclosed in the present invention to make a liquid detergent composition which exhibits improved anti-redeposition activity and improved low temperature storage stability such are exhibited by the present invention.